Olga Rudenko

This study addresses the pressing issue of utilising plastic from electronic waste as a filler to replace mineral sand. Currently, the use of plastic in construction concrete is limited due to a significant deterioration in the mechanical properties of modified concrete when plastic filler is added at levels exceeding 15–20%. As a result of the research, it was established that the addition of a nano-preparation—fullerene—in amounts as low as 0.001% significantly improves the mechanical properties of concrete with plastic aggregate. Replacing 50% of the mineral aggregate with plastic aggregate, combined with the addition of fullerene at a concentration of 0.01% of the mixing water mass, more than doubles the mechanical properties of the concrete compared to concrete without the nano-additive, with compressive strength increasing by 65.2%, from 16.33 MPa to 26.97 MPa. The impact strength and freeze–thaw resistance of the concrete were also significantly increased. This makes it possible to use concrete with a high plastic aggregate content of up to 50% without a significant reduction in mechanical properties. The use of machine learning and AI data processing methods such as AdaBoost and Random Forest allows for highly accurate prediction of the characteristics of the resulting materials, with a coefficient of determination (R²) for the resulting models close to 1.

This article discusses possible approaches to recycling electronic waste, with a focus on the main components of a personal computer (PC) system unit (SU). The study makes a significant contribution to solving the problem of natural resource depletion and environmental pollution. The article evaluates the possibility of commercial extraction of valuable metals without the use of reagents, complex processes, and equipment, as well as the utilization of plastic electronic waste (e-waste) in the construction industry. The proposed scheme for recycling the main components of printed circuit boards (PCBs) allows aluminum and copper alloys to be extracted from metal elements. Recycled PCBs provide raw materials containing more than 35.5% copper and other valuable metals. The plastic used in the production of control printed circuit boards is proposed to be used as an additive for construction concrete. When 40–50% of plastic is added to the mass of sand, concrete samples of grades M250–M200 can be obtained. And with a plastic content of 10–20% of the sand mass, concrete grades M350–M300 are obtained, which can be used for foundations and monolithic construction of low-rise buildings. A preliminary assessment of the toxicity of concrete has shown that it is safe. A preliminary assessment of the concrete’s toxicity revealed that it is safe. An initial evaluation of the commercial feasibility of processing the main components of the SU PC revealed the possibility of obtaining funds of approximately $3183.7 per 1000 SUs, without the use of complex processing schemes. The use of secondary metals will significantly reduce CO₂ emissions. The need for this study is driven by the high relevance of the issue of electronic waste disposal. Despite numerous studies in this area, the amount of waste worldwide is growing, which indicates the low effectiveness of existing methods.

The article presents the results of studies on forecasting the compressive strength and density of aerated ash concrete. A theoretical review was conducted on the variability of strength and density of cellular concretes when selecting their compositions. A series of experiments was conducted to study the dynamics of changes in the compressive strength and density of non-autoclaved gas-ash concrete during the initial stages of hardening under natural conditions and after thermal treatment to select a composition of the specified quality. It was revealed that it is possible to control both the strength and the density at the early stages of hardening to forecast these parameters at the design age of 28 days. It was established that the compressive strength of aerated ash concrete samples hardening under natural conditions increased by an average of 42.62% at the design age compared to the strength at 7 days, while the density decreased on average by 19.19%. For aerated ash concrete samples that underwent thermal treatment (steaming), the increase in strength averaged 34.67%, and the decrease in density was 11.07%. The obtained results are of practical value for scientists and engineers engaged in the development of cellular concrete compositions.

Non-autoclaved aerated concrete (NAAC) is gaining attention for its strength-to-weight ratio and sustainability benefits. Produced by incorporating a blowing agent into a binder, aggregate, and water mixture, NAAC offers a lightweight and porous construction material. Ash and slag waste (ASW), primarily composed of silicon, aluminum, iron, and calcium oxides, presents significant potential as a sustainable additive. However, industrial-scale processing of ASW still needs to be explored in Kazakhstan. This study evaluates the feasibility of utilizing ASW from the Ust-Kamenogorsk Thermal Power Plant to produce earthquake-resistant NAAC. Incorporating 31.5% ASW by weight optimizes compressive strength, achieving 2.35 MPa and significantly improving the mechanical properties. Chemical and microstructural analyses confirm ASW’s suitability as a construction material. The study also introduces innovative processing methods and explores convolutional neural network models for predicting material structure changes, providing insights into optimizing production processes. The findings address the research objectives by confirming the viability of ASW in NAAC production and demonstrating its potential for sustainable construction. The results offer a pathway for industrial-scale applications, contributing to waste utilization and resource conservation.

This study is devoted to the synthesis of aerated concrete by a non-autoclave method using ash from thermal power plants and a nanopreparation. Fullerenol-m was used as a nanopreparation. The fullerenol-m content in the sealing water of aerated concrete changed in the range of 0.00 ÷ 0.03 mas.%. The main performance characteristics of the nanostructured aerated concrete were studied, namely the compressive strength, impact toughness, thermal conductivity, density and moisture content. A significant improvement in the performance characteristics of the nanomodified aerated concrete compared to unmodified samples was demonstrated, which was most clearly manifested as an increase in impact toughness by several (three to five) times. The best performance characteristics of the modified aerated concrete were observed at a fullerenol-m concentration relative to the added cement within 0.022–0.028 wt.%. The authors attribute such a strong change and improvement in the physical, chemical and operational properties of aerated concrete when modified with fullerenol-m to the fact that fullerenol-m (a few thousandths of wt.%) has a very strong structuring effect on the sealing water and, as a consequence, on the resulting aerated concrete.